Ladder



I UNITED STATES PATENT EErcE;

CALEB H. JACKSON, OF ALLEGHENY, ASSIGNOR TO THE UNION S\VITCH AND SIGNALCOMPANY, OF PITTSBURG, PENNSYLVANIA.

LADDER.

SEECIPICATION forming part of Letters Patent No. 347,608, dated August17, 1886.

Application filed February 21, 1886. Serial No. 193,031. (No model.)

To all whom it may concern:

Be it known that I, CALEB H. JAoKsoN, residing at Allegheny, in thecounty of Allegheny and State of Pennsylvania, a citizen of the UnitedStates, have invented or discovered a certain new and useful Improvementin Lad ders, of which improvement the following is a specification.

In the accompanying drawings, which make part of this specification,Figure 1 is a view in perspective of a ladder embodying my invention;Fig. 2, a transverse section on an enlarged scale through the same; Fig.3. a view in perspective of one of the side bars, and Fig. 4 a similarview of a rung detached.

The object of my invention is to provide a metallic ladder speciallydesigned for use in connection with railroad signal-posts, which shallbe of simple and inexpensive construction, substantial, and durable.

To this end my invention, generally stated, consists in a ladderformedof longitudinallyslotted sidebars connected by transverse rungs orsteps, having tongues passing through the slots of the side bars andriveted over on the outside thereof. I

Theimprovement claimed is hereinafter fully set forth.

In the practice of my invention the two side bars, 1, are formed fromplates or bars of iron, of suitable width and thickness to properlysustain ,without deflection when connected, the load to which they willbe subjected, and of any desired length which can be convenientlyhandled in a'machine-shop. A series of rectangular longitudinal slots,2, is punched centrally in each of the bars, two or more bars beingsimultaneously operated on, according to the capacity of the machine.The slots 2, which are designedto receive the ends of the rungs, arespaced at such determined distance apart as may be desired fortheloeation of the rungs, and after the punching of the rungslots thebars 1 are cut into lengths proper to form the ladders desired, andcurved longitudinally adjacent to one end for attachment to asupporting-post, 3.

To form the rungs 4 a rectangular bar or strip of iron is cut intolengths or sections slightly greater than the width desired for theladder, and tongues or tenons 5, of such width as to pass through one ofthe slots 2 of the side bars, are preferably formed upon the ends of therung-sections, this operation being best effected by punching from therungs a rectangular piece at each corner, the portions thus removedbeing indicated by the dotted lines in Fig. 4. As two or more sectionsmay be punched simultaneously, the tongues can be readily andinexpensively formed.

The side bars, 1, and rungs 4 are connected and the ladder completed inreadiness for attachment to a post, 3, by passing the tongues 5 of therungs through opposite slots, 2,0f the side bars, and riveting over theprojecting ends of the tongues, at the inner ends of which the shouldersformed by the removal of the corner pieces bear against the inner sidesof the side bar's- If the rungs are unprovided with tongues, pins may bepassed through them or swells formed upon them adjacent to their ends tomaintain the side bars at the desired distance apart. The rungs and sidebars are thus firmly united without the use of separate rivets or otherextraneous fastenings, and corresponding lightness and economy ofmaterial is attained without involving any sacrifice of proper strengthand stiffness or liability to displacement of the parts. The curvedupper ends of the side bars are secured to the post 3 bybolts 6, and theladder,which is preferably outwardly inclined toward its lower end, isconnected at or near the same to the post by braces 7, bolted to thepost, and bolted or riveted to the side bars, intermediate braces, 8,being applied toinsure steadiness, it the length of the ladder is suchas to render them desirable.

I am aware that laddershaving the ordinary cylindrical rungs secured tothe side bars by riveting over their ends have been heretofore known,and do not, therefore, broadly claim such construction, my improvementbeing confined to that in which a rectangular rung end and a similarslot or socket are combined with ariveted connection, andin which, inaddition to attaining an economy of material, the turning of the rungsin thehauds of persons using the ladder is effectively prevented.

I claim herein as my invention 1. The combination, in ametallie ladder,of a pair of loiigitudinally-slotted side bars and a series of rungs orsteps of rectangular seeby shoulders at theinner ends of the tongues,

tion passing through the slots of the side bars and being held to theside bars by riveted or and riveted over on the outer sides thereof,turned-over edges on the outer sides thereof,

substantially as set forth. substantially as set forth. I 5 5 2. Thecombination, in a metallicladder, of In testimony whereof I havehereunto set a pair oflongitudinally-slotted side bars and my hand.

a series of rungs or steps of rectangular section having each of theirends cut away at top and bottom to form tongues or tenons passingVitnesses:

[0 through the slots of the side bars, said rungs J. SNOWDEN BELL,

bearing against theinner sides of the sidebars R. H. \VHITTLESEY.

CALEB II. JACKSON.

